By Wayne Lanier, Ph.D.
Your average five-year-old in the West Texas oil fields knows the “geology of oil.” His family is probably in the business, so he knows about oil. He knows the history of West Texas about as well as a college geology major. Most of us don’t, so I will put this story in context.
In 1968, I returned to the United States after four years living and working in London. To get around, I bought a VW “Thing.” Its design is based on the German command car of WWII. It did not sell well, so was very cheap. I decided to visit my uncle, who lived in Midland, Texas. He was retired and living off his oil wells. I had not seen him in some years.
During the visit we talked of Carlsbad Cavern, a nearby attraction in New Mexico. I decided to drive over to Carlsbad and tour the cavern, which I had not seen since childhood.
An Unexpected “Norther”
When I came out of the cavern darkness had fallen and so had snow from a “Norther.” A “Norther” is a blizzard in the 6,000-feet high flat land of the Llano. Llano runs north from New Mexico and Texas all the way to Canada. I found the two local motels full, with beds even in the hallways. No room at the Inn.
So, in the darkness, I filled the gas tank and started the 160-mile drive back to Midland. The “Thing” had a canvass top, and a separate gasoline heater instead of drawing heat from the air-cooled engine.
Even with the heater on, it was dreadfully cold. The snow continued to fall. It was hard to see the road. Hours passed and the gas gauge continued to fall. You don’t stop in a Norther; if you do they dig your body out of the snow when it’s all over. Suddenly I topped a rise and saw hundreds of flares to my right. I had come to the big oil field outside Midland. I was safe. Even if I ran out of gas, I could hike over and sleep under the warmth of a flare.
The Permian Basin
Well, this is where the geology comes in. We have to think first about how oil comes to be. The oil in that field was in a rock formation called the Permian Basin. The Earth’s geological history is divided into periods. The Permian Period began about 350-million years ago and came to a close about 250-million years ago, thus comprising about 100-million years.
At that time continental drift had pushed the earlier continents together into one single continent now called Pangea. Pangea encircled a shallow sea, called the Tethys Sea. As continental drift continued, Pangea was pulled apart. One part, consisting of some upland above the sea basin drifted to a position where Russia is today and came to be recognized as a distinctive rock formation, named after the town of Perm – The Permian Formation.
Another part, including both upland and part of the shallow sea, drifted around the world to the present location of west Texas – the Permian Basin. The rim was pushed farther up by this process to become the present 3,000-foot upland where Midland is now located. The sea was covered by other continental material in a series of continental collisions and now lies from several hundred to several thousand feet below the plain.
During the latter part of the Permian’s 100-million years, the sea life in the shallow Tethys Sea lived and died. Fish and vegetation remains settled in the mud to be covered by increasing layers of mud, then rock at greater and greater pressures. This vast amount of accumulating biological material became the west Texas oil field over the millions of years.
Pumping Oil, but Flaring Gas
Oil deep in the earth is under enormous pressure. Its gas component stays dissolved in the oil, even when the oil rises to the surface. At the surface, the gas boils off the oil. It can be captured and piped to homes, but out in West Texas, as in most oil fields around the world, there aren’t many homes nearby. Piping the gas would cost more than its market value. So it is burned off in a flare. This is true for oil fields all over the world.
The scientific journal Science featured a “Policy Forum” article on such flares in August. The article’s authors examined data from 8,966 on-stream oil fields around the world (about 96% of world production). The total atmospheric carbon production from these burning flares amounts to 1.7-gigatonnes, a figure that will increase as oil fields age, to 23 percent of the total atmospheric carbon production in the next decades. Most of this production is too far away from population centers to support the cost of collecting and shipping this gas, either by pipeline or tankers. As long as we produce oil, this increase in atmospheric carbon will continue.
Courtesy of Rossmoor News, October 10, 2018 edition. Email Wayne Lanier at firstname.lastname@example.org